#include<stdio.h>
int main(){
    int n,m;
    scanf("%d %d",&n,&m);
    if(n<=0||m<=0){
        printf("invalid input");
        return 0;
    } 
    int adj[101][101]={0};
    for(int i=0;i<=m;i++){
        int u,v;
        scanf("%d %d",&u,&v);
        if(u<=0||v<=0){
            printf("invalid input");
            return 0;
        }
        adj[u][v]=1;
        adj[v][u]=1;
    }
    int start;
    scanf("%d",&start);
    if(start<=0){
        printf("Invalid input");
        return 0;
    }
    int visited[101]={0};
    int queue[101]=front=0,rear=0;
    
    queue[rear++]=start;
    visited[start]=1;
    
    while(front<rear){
        int curr=queue[front++];
        printf("%d",curr);
        
        for(int i=1;i<=n;i++){
            if(adj[curr][i]==1 && !visited[i]){
                visited[i]=1;
                queue[rear++]=1;
                
            }
        }
    }
    return 0;
}